This invention relates to an apparatus for controlling the amount of fuel supplied to the engine upstream of its intake manifold connected to a plurality of cylinders with supplemental fuel during a demand for engine acceleration.
It is the current practice to provide a good engine acceleration performance by supplying supplemental fuel to the engine in response to a demand for engine acceleration. However, this practice cannot be applied directly to internal combustion engines of the single point injection (SPI) type having a single fuel injector provided for supplying fuel into the engine upstream of its intake manifold connected to a plurality of cylinders without a serious problem resulting from the fact that a great amount of fuel is collected on the inner wall of the intake manifold during wide-open throttle conditions. If engine acceleration is demanded again in a short time after a wide-open throttle condition continues for a long time, the collected fuel will be drawn into the cylinders to create an overrich mixture in the cylinders, causing increased HC and CO emissions.